문제
링크
풀이
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
string add(string a, string b) {
reverse(a.begin(), a.end());
reverse(b.begin(), b.end());
string c = "";
int carry = 0;
for (int i=0; i<max(a.length(), b.length()); i++) {
int sum = carry;
if (i < a.length()) sum += a[i] - '0';
if (i < b.length()) sum += b[i] - '0';
c += (sum % 10) + '0';
carry = sum / 10;
}
if (carry) c += carry + '0';
reverse(c.begin(), c.end());
return c;
}
void solve(void) {
vector<string> dp(251, "");
dp[0] = "1";
dp[1] = "1";
for (int i=2; i<=250; i++) {
dp[i] = add(add(dp[i-1], dp[i-2]), dp[i-2]);
}
int n;
while (cin >> n) {
cout << dp[n] << "\n";
}
}
int main(void) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
solve();
return 0;
}